Following one of the SO answer links in the sibling comment, the front UK.gov page, in 2013, had 1.1% of visitors with JS not-functioning. 0.2% of the visitors

Following one of the SO answer links in the sibling comment, the front UK.gov page, in 2013, had 1.1% of visitors with JS not-functioning. 0.2% of the visitors either explicitly disabled JS or were using browsers that didn't support it. 0.9% had JS, but it did not work for whatever reason. The author supposes corporate or local JS blocks or malfunctioning browser addons that effectively disable JS functionality. https://gds.blog.gov.uk/2013/10/21/how-many-people-are-missing-out-on-javascript-enhancement/ https://gds.blog.gov.uk/2013/10/21/how-many-people-are-missi...